A wind power plant is as a rule at least a part of an electrical power supply e.g. of a region or a country and is therefore connected to a grid as the transmission and/or distribution system of the voltage and/or the power of the electrical power supply. In general, all power plants need electrical power to start up. Under stable operation conditions a power plant delivers then a voltage and/or power to the grid. Under normal circumstances the electrical power for a start up of a power plant is provided from the transmission and/or the distribution system, thus from the grid of the electrical power supply.
But there can situations arise e.g. a normal outage or a disaster in which a collapse of at least a part of the grid occurs so that all or some power plants shut down. In this case no electrical power is available from the grid to restart a power plant. Therefore a power system or an electrical power supply comprising power plants and a transmission and/or distribution grid requires some contingency arrangements to enable a restart in the event that all or a part of the electrical power supply was shut down. The process of restoring the electrical power supply is commonly referred to as a black or a cold start.
In “An Introduction to Black Start”, February 2001, Market Development, National Grid Company plc, is described that isolated so called black start power stations being started individually and gradually being reconnected to each other in order to form an interconnected electrical power supply or power system again. Under emergency conditions a black start station thereby receives the necessary electrical power for the restart and the start up respectively from a small auxiliary generating plant located on-site. Such an auxiliary generating plant can be a small gas turbine or a diesel plant, the minimum size of which is dependent on the size of the black start power station.